services/surfaceflinger/tests/unittests/TransactionTracingTest.cpp - platform/frameworks/native - Git at Google

 /*
  * Copyright 2021 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <gmock/gmock.h>
 #include <gtest/gtest.h>

 #include <gui/SurfaceComposerClient.h>
 #include <cstdint>
 #include "Client.h"

 #include <layerproto/LayerProtoHeader.h>
 #include "FrontEnd/LayerCreationArgs.h"
 #include "FrontEnd/Update.h"
 #include "Tracing/LayerTracing.h"
 #include "Tracing/TransactionTracing.h"

 using namespace android::surfaceflinger;

 namespace android {

 class TransactionTracingTest : public testing::Test {
 protected:
     static constexpr size_t SMALL_BUFFER_SIZE = 1024;
     TransactionTracing mTracing;

     void flush() { mTracing.flush(); }
     perfetto::protos::TransactionTraceFile writeToProto() { return mTracing.writeToProto(); }

     perfetto::protos::TransactionTraceEntry bufferFront() {
         std::scoped_lock<std::mutex> lock(mTracing.mTraceLock);
         perfetto::protos::TransactionTraceEntry entry;
         entry.ParseFromString(mTracing.mBuffer.front());
         return entry;
     }

     void queueAndCommitTransaction(int64_t vsyncId) {
         frontend::Update update;
         TransactionState transaction;
         transaction.id = static_cast<uint64_t>(vsyncId * 3);
         transaction.originUid = 1;
         transaction.originPid = 2;
         mTracing.addQueuedTransaction(transaction);
         std::vector<TransactionState> transactions;
         update.transactions.emplace_back(transaction);
         mTracing.addCommittedTransactions(vsyncId, 0, update, {}, false);
         flush();
     }

     void verifyEntry(const perfetto::protos::TransactionTraceEntry& actualProto,
                      const std::vector<TransactionState>& expectedTransactions,
                      int64_t expectedVsyncId) {
         EXPECT_EQ(actualProto.vsync_id(), expectedVsyncId);
         ASSERT_EQ(actualProto.transactions().size(),
                   static_cast<int32_t>(expectedTransactions.size()));
         for (uint32_t i = 0; i < expectedTransactions.size(); i++) {
             const auto expectedTransaction = expectedTransactions[i];
             const auto protoTransaction = actualProto.transactions(static_cast<int32_t>(i));
             EXPECT_EQ(protoTransaction.transaction_id(), expectedTransaction.id);
             EXPECT_EQ(protoTransaction.pid(), expectedTransaction.originPid);
             for (uint32_t i = 0; i < expectedTransaction.mergedTransactionIds.size(); i++) {
                 EXPECT_EQ(protoTransaction.merged_transaction_ids(static_cast<int32_t>(i)),
                           expectedTransaction.mergedTransactionIds[i]);
             }
         }
     }

     LayerCreationArgs getLayerCreationArgs(uint32_t layerId, uint32_t parentId,
                                            uint32_t layerIdToMirror, uint32_t flags,
                                            bool addToRoot) {
         LayerCreationArgs args;
         args.sequence = layerId;
         args.parentId = parentId;
         args.layerIdToMirror = layerIdToMirror;
         args.flags = flags;
         args.addToRoot = addToRoot;
         return args;
     }
 };

 TEST_F(TransactionTracingTest, addTransactions) {
     std::vector<TransactionState> transactions;
     transactions.reserve(100);
     for (uint64_t i = 0; i < 100; i++) {
         TransactionState transaction;
         transaction.id = i;
         transaction.originPid = static_cast<int32_t>(i);
         transaction.mergedTransactionIds = std::vector<uint64_t>{i + 100, i + 102};
         transactions.emplace_back(transaction);
         mTracing.addQueuedTransaction(transaction);
     }

     // Split incoming transactions into two and commit them in reverse order to test out of order
     // commits.
     int64_t firstTransactionSetVsyncId = 42;
     frontend::Update firstUpdate;
     firstUpdate.transactions =
             std::vector<TransactionState>(transactions.begin() + 50, transactions.end());
     mTracing.addCommittedTransactions(firstTransactionSetVsyncId, 0, firstUpdate, {}, false);

     int64_t secondTransactionSetVsyncId = 43;
     frontend::Update secondUpdate;
     secondUpdate.transactions =
             std::vector<TransactionState>(transactions.begin(), transactions.begin() + 50);
     mTracing.addCommittedTransactions(secondTransactionSetVsyncId, 0, secondUpdate, {}, false);
     flush();

     perfetto::protos::TransactionTraceFile proto = writeToProto();
     ASSERT_EQ(proto.entry().size(), 2);
     verifyEntry(proto.entry(0), firstUpdate.transactions, firstTransactionSetVsyncId);
     verifyEntry(proto.entry(1), secondUpdate.transactions, secondTransactionSetVsyncId);
 }

 class TransactionTracingLayerHandlingTest : public TransactionTracingTest {
 protected:
     void SetUp() override {
         mTracing.setBufferSize(SMALL_BUFFER_SIZE);

         // add layers and add some layer transaction
         {
             frontend::Update update;
             update.layerCreationArgs.emplace_back(std::move(
                     getLayerCreationArgs(mParentLayerId, /*parentId=*/UNASSIGNED_LAYER_ID,
                                          /*layerIdToMirror=*/UNASSIGNED_LAYER_ID, /*flags=*/123,
                                          /*addToRoot=*/true)));
             update.layerCreationArgs.emplace_back(std::move(
                     getLayerCreationArgs(mChildLayerId, mParentLayerId,
                                          /*layerIdToMirror=*/UNASSIGNED_LAYER_ID, /*flags=*/456,
                                          /*addToRoot=*/true)));
             TransactionState transaction;
             transaction.id = 50;
             ResolvedComposerState layerState;
             layerState.layerId = mParentLayerId;
             layerState.state.what = layer_state_t::eLayerChanged;
             layerState.state.z = 42;
             transaction.states.emplace_back(layerState);
             ResolvedComposerState childState;
             childState.layerId = mChildLayerId;
             childState.state.what = layer_state_t::eLayerChanged;
             childState.state.z = 43;
             transaction.states.emplace_back(childState);
             mTracing.addQueuedTransaction(transaction);

             update.transactions.emplace_back(transaction);
             VSYNC_ID_FIRST_LAYER_CHANGE = ++mVsyncId;
             mTracing.addCommittedTransactions(VSYNC_ID_FIRST_LAYER_CHANGE, 0, update, {}, false);

             flush();
         }

         // add transactions that modify the layer state further so we can test that layer state
         // gets merged
         {
             TransactionState transaction;
             transaction.id = 51;
             ResolvedComposerState layerState;
             layerState.layerId = mParentLayerId;
             layerState.state.what = layer_state_t::eLayerChanged | layer_state_t::ePositionChanged;
             layerState.state.z = 41;
             layerState.state.x = 22;
             transaction.states.emplace_back(layerState);
             mTracing.addQueuedTransaction(transaction);

             frontend::Update update;
             update.transactions.emplace_back(transaction);
             VSYNC_ID_SECOND_LAYER_CHANGE = ++mVsyncId;
             mTracing.addCommittedTransactions(VSYNC_ID_SECOND_LAYER_CHANGE, 0, update, {}, false);
             flush();
         }

         // remove child layer
         mTracing.onLayerRemoved(2);
         VSYNC_ID_CHILD_LAYER_REMOVED = ++mVsyncId;
         queueAndCommitTransaction(VSYNC_ID_CHILD_LAYER_REMOVED);

         // remove layer
         mTracing.onLayerRemoved(1);
         queueAndCommitTransaction(++mVsyncId);
     }

     uint32_t mParentLayerId = 1;
     uint32_t mChildLayerId = 2;
     int64_t mVsyncId = 0;
     int64_t VSYNC_ID_FIRST_LAYER_CHANGE;
     int64_t VSYNC_ID_SECOND_LAYER_CHANGE;
     int64_t VSYNC_ID_CHILD_LAYER_REMOVED;
 };

 TEST_F(TransactionTracingLayerHandlingTest, addStartingState) {
     // add transactions until we drop the transaction with the first layer change
     while (bufferFront().vsync_id() <= VSYNC_ID_FIRST_LAYER_CHANGE) {
         queueAndCommitTransaction(++mVsyncId);
     }
     perfetto::protos::TransactionTraceFile proto = writeToProto();
     // verify we can still retrieve the layer change from the first entry containing starting
     // states.
     EXPECT_GT(proto.entry().size(), 0);
     EXPECT_EQ(proto.entry(0).transactions().size(), 1);
     EXPECT_EQ(proto.entry(0).added_layers().size(), 2);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).z(), 42);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).layer_id(), mChildLayerId);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).z(), 43);
 }

 TEST_F(TransactionTracingLayerHandlingTest, updateStartingState) {
     // add transactions until we drop the transaction with the second layer change
     while (bufferFront().vsync_id() <= VSYNC_ID_SECOND_LAYER_CHANGE) {
         queueAndCommitTransaction(++mVsyncId);
     }
     perfetto::protos::TransactionTraceFile proto = writeToProto();
     // verify starting states are updated correctly
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).z(), 41);
 }

 TEST_F(TransactionTracingLayerHandlingTest, removeStartingState) {
     // add transactions until we drop the transaction which removes the child layer
     while (bufferFront().vsync_id() <= VSYNC_ID_CHILD_LAYER_REMOVED) {
         queueAndCommitTransaction(++mVsyncId);
     }
     perfetto::protos::TransactionTraceFile proto = writeToProto();
     // verify the child layer has been removed from the trace
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 1);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
 }

 TEST_F(TransactionTracingLayerHandlingTest, startingStateSurvivesBufferFlush) {
     // add transactions until we drop the transaction with the second layer change
     while (bufferFront().vsync_id() <= VSYNC_ID_SECOND_LAYER_CHANGE) {
         queueAndCommitTransaction(++mVsyncId);
     }
     perfetto::protos::TransactionTraceFile proto = writeToProto();
     // verify we have two starting states
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);

     // Continue adding transactions until child layer is removed
     while (bufferFront().vsync_id() <= VSYNC_ID_CHILD_LAYER_REMOVED) {
         queueAndCommitTransaction(++mVsyncId);
     }
     proto = writeToProto();
     // verify we still have the parent layer state
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 1);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
 }

 class TransactionTracingMirrorLayerTest : public TransactionTracingTest {
 protected:
     void SetUp() override {
         mTracing.setBufferSize(SMALL_BUFFER_SIZE);

         // add layers and some layer transaction
         {
             frontend::Update update;
             update.layerCreationArgs.emplace_back(
                     getLayerCreationArgs(mLayerId, /*parentId=*/UNASSIGNED_LAYER_ID,
                                          /*layerIdToMirror=*/UNASSIGNED_LAYER_ID, /*flags=*/123,
                                          /*addToRoot=*/true));
             update.layerCreationArgs.emplace_back(
                     getLayerCreationArgs(mMirrorLayerId, UNASSIGNED_LAYER_ID,
                                          /*layerIdToMirror=*/mLayerId, /*flags=*/0,
                                          /*addToRoot=*/false));

             TransactionState transaction;
             transaction.id = 50;
             ResolvedComposerState layerState;
             layerState.layerId = mLayerId;
             layerState.state.what = layer_state_t::eLayerChanged;
             layerState.state.z = 42;
             transaction.states.emplace_back(layerState);
             ResolvedComposerState mirrorState;
             mirrorState.layerId = mMirrorLayerId;
             mirrorState.state.what = layer_state_t::eLayerChanged;
             mirrorState.state.z = 43;
             transaction.states.emplace_back(mirrorState);
             mTracing.addQueuedTransaction(transaction);

             update.transactions.emplace_back(transaction);
             mTracing.addCommittedTransactions(mVsyncId, 0, update, {}, false);
             flush();
         }
     }

     uint32_t mLayerId = 5;
     uint32_t mMirrorLayerId = 55;
     int64_t mVsyncId = 0;
     int64_t VSYNC_ID_FIRST_LAYER_CHANGE;
     int64_t VSYNC_ID_SECOND_LAYER_CHANGE;
     int64_t VSYNC_ID_CHILD_LAYER_REMOVED;
 };

 TEST_F(TransactionTracingMirrorLayerTest, canAddMirrorLayers) {
     perfetto::protos::TransactionTraceFile proto = writeToProto();
     // We don't have any starting states since no layer was removed from.
     EXPECT_EQ(proto.entry().size(), 1);

     // Verify the mirror layer was added
     EXPECT_EQ(proto.entry(0).transactions().size(), 1);
     EXPECT_EQ(proto.entry(0).added_layers().size(), 2);
     EXPECT_EQ(proto.entry(0).added_layers(1).layer_id(), mMirrorLayerId);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);
     EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).z(), 43);
 }

 // Verify we can write the layers traces by entry to reduce mem pressure
 // on the system when generating large traces.
 TEST(LayerTraceTest, canStreamLayersTrace) {
     perfetto::protos::LayersTraceFileProto inProto = LayerTracing::createTraceFileProto();
     inProto.add_entry();
     inProto.add_entry();

     std::string output;
     inProto.SerializeToString(&output);
     perfetto::protos::LayersTraceFileProto inProto2 = LayerTracing::createTraceFileProto();
     inProto2.add_entry();
     std::string output2;
     inProto2.SerializeToString(&output2);

     perfetto::protos::LayersTraceFileProto outProto;
     outProto.ParseFromString(output + output2);
     // magic?
     EXPECT_EQ(outProto.entry().size(), 3);
 }
 } // namespace android
	/*
	* Copyright 2021 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <gmock/gmock.h>
	#include <gtest/gtest.h>

	#include <gui/SurfaceComposerClient.h>
	#include <cstdint>
	#include "Client.h"

	#include <layerproto/LayerProtoHeader.h>
	#include "FrontEnd/LayerCreationArgs.h"
	#include "FrontEnd/Update.h"
	#include "Tracing/LayerTracing.h"
	#include "Tracing/TransactionTracing.h"

	using namespace android::surfaceflinger;

	namespace android {

	class TransactionTracingTest : public testing::Test {
	protected:
	static constexpr size_t SMALL_BUFFER_SIZE = 1024;
	TransactionTracing mTracing;

	void flush() { mTracing.flush(); }
	perfetto::protos::TransactionTraceFile writeToProto() { return mTracing.writeToProto(); }

	perfetto::protos::TransactionTraceEntry bufferFront() {
	std::scoped_lock<std::mutex> lock(mTracing.mTraceLock);
	perfetto::protos::TransactionTraceEntry entry;
	entry.ParseFromString(mTracing.mBuffer.front());
	return entry;
	}

	void queueAndCommitTransaction(int64_t vsyncId) {
	frontend::Update update;
	TransactionState transaction;
	transaction.id = static_cast<uint64_t>(vsyncId * 3);
	transaction.originUid = 1;
	transaction.originPid = 2;
	mTracing.addQueuedTransaction(transaction);
	std::vector<TransactionState> transactions;
	update.transactions.emplace_back(transaction);
	mTracing.addCommittedTransactions(vsyncId, 0, update, {}, false);
	flush();
	}

	void verifyEntry(const perfetto::protos::TransactionTraceEntry& actualProto,
	const std::vector<TransactionState>& expectedTransactions,
	int64_t expectedVsyncId) {
	EXPECT_EQ(actualProto.vsync_id(), expectedVsyncId);
	ASSERT_EQ(actualProto.transactions().size(),
	static_cast<int32_t>(expectedTransactions.size()));
	for (uint32_t i = 0; i < expectedTransactions.size(); i++) {
	const auto expectedTransaction = expectedTransactions[i];
	const auto protoTransaction = actualProto.transactions(static_cast<int32_t>(i));
	EXPECT_EQ(protoTransaction.transaction_id(), expectedTransaction.id);
	EXPECT_EQ(protoTransaction.pid(), expectedTransaction.originPid);
	for (uint32_t i = 0; i < expectedTransaction.mergedTransactionIds.size(); i++) {
	EXPECT_EQ(protoTransaction.merged_transaction_ids(static_cast<int32_t>(i)),
	expectedTransaction.mergedTransactionIds[i]);
	}
	}
	}

	LayerCreationArgs getLayerCreationArgs(uint32_t layerId, uint32_t parentId,
	uint32_t layerIdToMirror, uint32_t flags,
	bool addToRoot) {
	LayerCreationArgs args;
	args.sequence = layerId;
	args.parentId = parentId;
	args.layerIdToMirror = layerIdToMirror;
	args.flags = flags;
	args.addToRoot = addToRoot;
	return args;
	}
	};

	TEST_F(TransactionTracingTest, addTransactions) {
	std::vector<TransactionState> transactions;
	transactions.reserve(100);
	for (uint64_t i = 0; i < 100; i++) {
	TransactionState transaction;
	transaction.id = i;
	transaction.originPid = static_cast<int32_t>(i);
	transaction.mergedTransactionIds = std::vector<uint64_t>{i + 100, i + 102};
	transactions.emplace_back(transaction);
	mTracing.addQueuedTransaction(transaction);
	}

	// Split incoming transactions into two and commit them in reverse order to test out of order
	// commits.
	int64_t firstTransactionSetVsyncId = 42;
	frontend::Update firstUpdate;
	firstUpdate.transactions =
	std::vector<TransactionState>(transactions.begin() + 50, transactions.end());
	mTracing.addCommittedTransactions(firstTransactionSetVsyncId, 0, firstUpdate, {}, false);

	int64_t secondTransactionSetVsyncId = 43;
	frontend::Update secondUpdate;
	secondUpdate.transactions =
	std::vector<TransactionState>(transactions.begin(), transactions.begin() + 50);
	mTracing.addCommittedTransactions(secondTransactionSetVsyncId, 0, secondUpdate, {}, false);
	flush();

	perfetto::protos::TransactionTraceFile proto = writeToProto();
	ASSERT_EQ(proto.entry().size(), 2);
	verifyEntry(proto.entry(0), firstUpdate.transactions, firstTransactionSetVsyncId);
	verifyEntry(proto.entry(1), secondUpdate.transactions, secondTransactionSetVsyncId);
	}

	class TransactionTracingLayerHandlingTest : public TransactionTracingTest {
	protected:
	void SetUp() override {
	mTracing.setBufferSize(SMALL_BUFFER_SIZE);

	// add layers and add some layer transaction
	{
	frontend::Update update;
	update.layerCreationArgs.emplace_back(std::move(
	getLayerCreationArgs(mParentLayerId, /parentId=/UNASSIGNED_LAYER_ID,
	/layerIdToMirror=/UNASSIGNED_LAYER_ID, /flags=/123,
	/addToRoot=/true)));
	update.layerCreationArgs.emplace_back(std::move(
	getLayerCreationArgs(mChildLayerId, mParentLayerId,
	/layerIdToMirror=/UNASSIGNED_LAYER_ID, /flags=/456,
	/addToRoot=/true)));
	TransactionState transaction;
	transaction.id = 50;
	ResolvedComposerState layerState;
	layerState.layerId = mParentLayerId;
	layerState.state.what = layer_state_t::eLayerChanged;
	layerState.state.z = 42;
	transaction.states.emplace_back(layerState);
	ResolvedComposerState childState;
	childState.layerId = mChildLayerId;
	childState.state.what = layer_state_t::eLayerChanged;
	childState.state.z = 43;
	transaction.states.emplace_back(childState);
	mTracing.addQueuedTransaction(transaction);

	update.transactions.emplace_back(transaction);
	VSYNC_ID_FIRST_LAYER_CHANGE = ++mVsyncId;
	mTracing.addCommittedTransactions(VSYNC_ID_FIRST_LAYER_CHANGE, 0, update, {}, false);

	flush();
	}

	// add transactions that modify the layer state further so we can test that layer state
	// gets merged
	{
	TransactionState transaction;
	transaction.id = 51;
	ResolvedComposerState layerState;
	layerState.layerId = mParentLayerId;
	layerState.state.what = layer_state_t::eLayerChanged \| layer_state_t::ePositionChanged;
	layerState.state.z = 41;
	layerState.state.x = 22;
	transaction.states.emplace_back(layerState);
	mTracing.addQueuedTransaction(transaction);

	frontend::Update update;
	update.transactions.emplace_back(transaction);
	VSYNC_ID_SECOND_LAYER_CHANGE = ++mVsyncId;
	mTracing.addCommittedTransactions(VSYNC_ID_SECOND_LAYER_CHANGE, 0, update, {}, false);
	flush();
	}

	// remove child layer
	mTracing.onLayerRemoved(2);
	VSYNC_ID_CHILD_LAYER_REMOVED = ++mVsyncId;
	queueAndCommitTransaction(VSYNC_ID_CHILD_LAYER_REMOVED);

	// remove layer
	mTracing.onLayerRemoved(1);
	queueAndCommitTransaction(++mVsyncId);
	}

	uint32_t mParentLayerId = 1;
	uint32_t mChildLayerId = 2;
	int64_t mVsyncId = 0;
	int64_t VSYNC_ID_FIRST_LAYER_CHANGE;
	int64_t VSYNC_ID_SECOND_LAYER_CHANGE;
	int64_t VSYNC_ID_CHILD_LAYER_REMOVED;
	};

	TEST_F(TransactionTracingLayerHandlingTest, addStartingState) {
	// add transactions until we drop the transaction with the first layer change
	while (bufferFront().vsync_id() <= VSYNC_ID_FIRST_LAYER_CHANGE) {
	queueAndCommitTransaction(++mVsyncId);
	}
	perfetto::protos::TransactionTraceFile proto = writeToProto();
	// verify we can still retrieve the layer change from the first entry containing starting
	// states.
	EXPECT_GT(proto.entry().size(), 0);
	EXPECT_EQ(proto.entry(0).transactions().size(), 1);
	EXPECT_EQ(proto.entry(0).added_layers().size(), 2);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).z(), 42);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).layer_id(), mChildLayerId);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).z(), 43);
	}

	TEST_F(TransactionTracingLayerHandlingTest, updateStartingState) {
	// add transactions until we drop the transaction with the second layer change
	while (bufferFront().vsync_id() <= VSYNC_ID_SECOND_LAYER_CHANGE) {
	queueAndCommitTransaction(++mVsyncId);
	}
	perfetto::protos::TransactionTraceFile proto = writeToProto();
	// verify starting states are updated correctly
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).z(), 41);
	}

	TEST_F(TransactionTracingLayerHandlingTest, removeStartingState) {
	// add transactions until we drop the transaction which removes the child layer
	while (bufferFront().vsync_id() <= VSYNC_ID_CHILD_LAYER_REMOVED) {
	queueAndCommitTransaction(++mVsyncId);
	}
	perfetto::protos::TransactionTraceFile proto = writeToProto();
	// verify the child layer has been removed from the trace
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 1);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
	}

	TEST_F(TransactionTracingLayerHandlingTest, startingStateSurvivesBufferFlush) {
	// add transactions until we drop the transaction with the second layer change
	while (bufferFront().vsync_id() <= VSYNC_ID_SECOND_LAYER_CHANGE) {
	queueAndCommitTransaction(++mVsyncId);
	}
	perfetto::protos::TransactionTraceFile proto = writeToProto();
	// verify we have two starting states
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);

	// Continue adding transactions until child layer is removed
	while (bufferFront().vsync_id() <= VSYNC_ID_CHILD_LAYER_REMOVED) {
	queueAndCommitTransaction(++mVsyncId);
	}
	proto = writeToProto();
	// verify we still have the parent layer state
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 1);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(0).layer_id(), mParentLayerId);
	}

	class TransactionTracingMirrorLayerTest : public TransactionTracingTest {
	protected:
	void SetUp() override {
	mTracing.setBufferSize(SMALL_BUFFER_SIZE);

	// add layers and some layer transaction
	{
	frontend::Update update;
	update.layerCreationArgs.emplace_back(
	getLayerCreationArgs(mLayerId, /parentId=/UNASSIGNED_LAYER_ID,
	/layerIdToMirror=/UNASSIGNED_LAYER_ID, /flags=/123,
	/addToRoot=/true));
	update.layerCreationArgs.emplace_back(
	getLayerCreationArgs(mMirrorLayerId, UNASSIGNED_LAYER_ID,
	/layerIdToMirror=/mLayerId, /flags=/0,
	/addToRoot=/false));

	TransactionState transaction;
	transaction.id = 50;
	ResolvedComposerState layerState;
	layerState.layerId = mLayerId;
	layerState.state.what = layer_state_t::eLayerChanged;
	layerState.state.z = 42;
	transaction.states.emplace_back(layerState);
	ResolvedComposerState mirrorState;
	mirrorState.layerId = mMirrorLayerId;
	mirrorState.state.what = layer_state_t::eLayerChanged;
	mirrorState.state.z = 43;
	transaction.states.emplace_back(mirrorState);
	mTracing.addQueuedTransaction(transaction);

	update.transactions.emplace_back(transaction);
	mTracing.addCommittedTransactions(mVsyncId, 0, update, {}, false);
	flush();
	}
	}

	uint32_t mLayerId = 5;
	uint32_t mMirrorLayerId = 55;
	int64_t mVsyncId = 0;
	int64_t VSYNC_ID_FIRST_LAYER_CHANGE;
	int64_t VSYNC_ID_SECOND_LAYER_CHANGE;
	int64_t VSYNC_ID_CHILD_LAYER_REMOVED;
	};

	TEST_F(TransactionTracingMirrorLayerTest, canAddMirrorLayers) {
	perfetto::protos::TransactionTraceFile proto = writeToProto();
	// We don't have any starting states since no layer was removed from.
	EXPECT_EQ(proto.entry().size(), 1);

	// Verify the mirror layer was added
	EXPECT_EQ(proto.entry(0).transactions().size(), 1);
	EXPECT_EQ(proto.entry(0).added_layers().size(), 2);
	EXPECT_EQ(proto.entry(0).added_layers(1).layer_id(), mMirrorLayerId);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes().size(), 2);
	EXPECT_EQ(proto.entry(0).transactions(0).layer_changes(1).z(), 43);
	}

	// Verify we can write the layers traces by entry to reduce mem pressure
	// on the system when generating large traces.
	TEST(LayerTraceTest, canStreamLayersTrace) {
	perfetto::protos::LayersTraceFileProto inProto = LayerTracing::createTraceFileProto();
	inProto.add_entry();
	inProto.add_entry();

	std::string output;
	inProto.SerializeToString(&output);
	perfetto::protos::LayersTraceFileProto inProto2 = LayerTracing::createTraceFileProto();
	inProto2.add_entry();
	std::string output2;
	inProto2.SerializeToString(&output2);

	perfetto::protos::LayersTraceFileProto outProto;
	outProto.ParseFromString(output + output2);
	// magic?
	EXPECT_EQ(outProto.entry().size(), 3);
	}
	} // namespace android